Light source unit and projection-type display

ABSTRACT

A light source unit of the disclosure includes a plurality of light source sections, a light quantity detector, and a controller. The plurality of light source sections emit rays of colors different from each other. The light quantity detector receives a plurality of color rays emitted by the plurality of light source sections as spatially common light. The controller controls a light emission timing of each of the plurality of light source sections and a gain of the light quantity detector, and measures light quantities of the respective plurality of color rays at different timings and with different gains on a basis of a detection result of the light.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a continuation application of U.S. patentapplication Ser. No. 16/056,684, filed Aug. 7, 2018, which is acontinuation application of U.S. patent application Ser. No. 15/525,452,filed May 9, 2017, which is a national stage entry of PCT/JP2015/077438,filed Sep. 29, 2015, and claims the benefit of priority from JapanesePatent Application No. JP 2014-237818, filed Nov. 25, 2014 which arehereby incorporated by reference in their entirety for all purposes.

TECHNICAL FIELD

The disclosure relates to a light source unit that emits rays of aplurality of colors, and a projection-type display that projects animage by using the rays from the light source unit.

BACKGROUND ART

In recent years, a projector (a projection-type display) that projectsan image onto a screen has been widely used not only in offices but alsoat home. The projector generates image light by modulating light from alight source with a light valve (a spatial modulation device), andperforms display by projecting the generated image light onto a screen.

CITATION LIST Patent Literature

PTL 1: Japanese Unexamined Patent Application Publication No.2012-104489 P 2011-96851A

SUMMARY OF THE INVENTION

An image projected from a projector is expected to be constant in whitebalance. When using light sources that emit rays of differentwavelengths (e.g., red, green, and blue), it is necessary to maintain aratio of a light quantity output of each of the light sources. To thisend, feedback control of the light source is performed to control alight quantity output as appropriate by measuring a light quantity ofthe light source.

PTL 1 proposes classifying a plurality of semiconductor light-emissioneach serving as a light source into light-emission device groups for therespective colors, and detecting optical intensities for respectiveoptical device groups with one light quantity detector, by causing theoptical device groups to emit light sequentially in a time series. PTL 1proposes performing feedback control of a driving current of theplurality of semiconductor light-emission devices, on the basis of aresult of optical devices intensity sampling with the one light quantitydetector. However, in the feedback control discussed in PTL 1, gain ofthe light quantity detector is not changed, when the optical intensityfor each of the plurality of colors is detected with the one lightquantity detector. It is therefore difficult to secure a sufficientdynamic range for each of the colors, which leads to a decrease inresolution of a sampling value, thereby making it difficult to performprecise feedback control of the light source. At worst, contrast of thelight quantity of the light source periodically changes, which causesflicker.

In addition, the feedback control in PTL 1 is performed by classifyingthe plurality of semiconductor light-emission devices into thelight-emission device groups of the respective colors, and collectivelysampling light quantities for each of the optical device groups.However, the individual semiconductor light-emission devices are uneven.It is therefore difficult to perform precise feedback control, unlesssampling is performed for each of the semiconductor light-emissiondevices even if the colors thereof are identical.

Hence, it is desirable to provide a light source unit and aprojection-type display that make it possible to precisely measure alight quantity of each of a plurality of color rays with one lightquantity detector.

A light source unit according to one embodiment of the disclosureincludes: a plurality of light source sections that emit rays of colorsdifferent from each other; a light quantity detector that receives therays of colors emitted by the plurality of light source sections in aspatially-common manner; and a controller that controls a light emissiontiming of each of the plurality of light source sections and a gain ofthe light quantity detector, and measures light quantities of therespective rays of colors at different timings and with different gainson the basis of a detection result of the light quantity detector.

A projection-type display according to one embodiment of the disclosureincludes: a plurality of light source sections that emit rays of colorsdifferent from each other; at least one image display device thatmodulates the rays of colors emitted by the plurality of light sourcesections on the basis of an image signal, and outputs the modulatedrays; a light quantity detector that receives the rays of colors in aspatially-common manner; and a controller that controls a light emissiontiming of each of the plurality of light source sections and a gain ofthe light quantity detector, and measures light quantities of therespective rays of colors at different timings and with different gainson the basis of a detection result of the light quantity detector.

In each of the light source unit and the projection-type displayaccording to the respective embodiments of the disclosure, the lightemission timing of each of the plurality of light source sections andthe gain of the light quantity detector are controlled, and thereby, thelight quantities of the respective rays of colors are measured atdifferent timings and with different gains on the basis of the detectionresult of the light quantity detector.

Another light source unit according to one embodiment of the disclosureincludes: a plurality of light source sections that emit rays of colorsdifferent from each other; a light quantity detector that receives therays of colors emitted by the plurality of light source sections in aspatially-common manner; and a controller that controls a light emissiontiming of each of the plurality of light source sections, and measureslight quantities of the respective rays of colors at different timingson the basis of a detection result of the light quantity detector, inwhich the controller causes the plurality of light source sections toemit the rays simultaneously, in a period except for a period in whichthe measurement of the light quantity of each of the rays of colors isperformed, and extinguishes only one light source section that emits theray of color to be measured among the plurality of light source sectionsfor a predetermined period, in the period in which the measurement ofthe light quantity of each of the rays of colors is performed.

Another projection-type display according to one embodiment of thedisclosure includes: a plurality of light source sections that emit raysof colors different from each other; a plurality of image displaydevices that modulate the respective rays of colors emitted by theplurality of light source sections, on the basis of an image signal, andoutput the respective modulated rays for the respective rays of colors;a light quantity detector that receives the rays of colors in aspatially-common manner; and a controller that controls a light emissiontiming of each of the plurality of light source sections, and measureslight quantities of the respective rays of colors at different timingson the basis of a detection result of the light quantity detector, inwhich the controller causes the plurality of light source sections toemit the rays simultaneously, in a period except for a period in whichthe measurement of the light quantity of each of the rays of colors isperformed, and extinguishes only one light source section that emits aray of color to be measured among the plurality of light source sectionsfor a predetermined period, in the period in which the measurement ofthe light quantity of each of the rays of colors is performed.

In each of the another light source unit and the another projection-typedisplay according to the respective embodiments of the disclosure, theplurality of light source sections are caused to emit the rayssimultaneously, in the period except for the period in which themeasurement of the light quantity of each of the rays of colors isperformed, and only one light source section that emits the ray of colorto be measured among the plurality of light source sections isextinguished for the predetermined period, in the period in which themeasurement of the light quantity of each of the rays of colors isperformed.

According to each of the light source unit and the projection-typedisplay according to the respective embodiments of the disclosure, theplurality of rays of colors are caused to be received by the lightquantity detector in the spatially-common manner, and the lightquantities of the respective plurality of rays of colors are measured atdifferent timings and with different gains. It is therefore possible tomeasure the light quantities of the plurality of rays of colorsprecisely with the single light quantity detector.

According to each of the another light source unit and the anotherprojection-type display according to the respective embodiments of thedisclosure, the plurality of rays of colors are caused to be received bythe light quantity detector in the spatially-common manner, and only onelight source section that emits a ray of color to be measured isextinguished for the predetermined period among the plurality of lightsource sections. The light quantities of the respective rays of colorsare thereby measured at different timings. It is therefore possible tomeasure the light quantities of the plurality of rays of colorsprecisely with the single light quantity detector.

It is to be noted that the effects described above are not necessarilylimitative, and any of effects described in the disclosure may beprovided.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a configuration diagram illustrating an example of an overallconfiguration of a projection-type display according to a firstembodiment of the disclosure.

FIG. 2 is a block diagram illustrating a configuration example of acontrol system in the projection-type display according to the firstembodiment.

FIG. 3 is an explanatory diagram illustrating an example of each oflight emission timings of light source sections and light-quantitysampling operation in the first embodiment.

FIG. 4 is a flowchart illustrating an example of the light-quantitysampling operation in the first embodiment.

FIG. 5 is an explanatory diagram illustrating an example of each oflight emission timings of light source sections and light-quantitysampling operation in a second embodiment.

FIG. 6 is an explanatory diagram illustrating an example of each oflight emission timings of light source sections and light-quantitysampling operation in a third embodiment.

FIG. 7 is an explanatory diagram illustrating an example of each oflight emission timings of light source sections and light-quantitysampling operation in a modification example of the third embodiment.

FIG. 8 is an explanatory diagram illustrating an example of each oflight emission timings of light source sections and light-quantitysampling operation in a fourth embodiment.

FIG. 9 is an explanatory diagram illustrating an example of each oflight emission timings of light source sections and light-quantitysampling operation in a modification example of the fourth embodiment.

FIG. 10 is a configuration diagram illustrating an example of a lightquantity detector in a fifth embodiment.

FIG. 11 is a configuration diagram illustrating an example of an overallconfiguration of a projection-type display according to a sixthembodiment.

FIG. 12 is an explanatory diagram illustrating an example of each oflight emission timings of light source sections and light-quantitysampling operation in the sixth embodiment.

MODES FOR CARRYING OUT THE INVENTION

Some embodiments of the disclosure will be described below in detail inthe following order, with reference to the drawings.

1. First Embodiment (an embodiment of a case where a plurality of lightsource sections that emit rays of colors different from each other areprovided) (FIG. 1 to FIG. 4)

1.1 Overall Configuration of Projection-Type Display 1.2 Configurationand Operation of Control System 1.2.1 Configuration Example of ControlSystem 1.2.2 Light Emission Timing of Light Source Section andLight-Quantity Sampling Operation 1.3 Effects

2. Second Embodiment (an embodiment in which two light sources of samecolor are provided) (FIG. 5)

2.1 Configuration and Operation 2.2 Effects

3. Third Embodiment (an embodiment in which three or more light sourcesof same color are provided) (FIG. 6 and FIG. 7)

3.1 Configuration and Operation 3.2 Effects 3.3 Modification Example

4. Fourth Embodiment (an embodiment in which sampling is performed aplurality of times for one light source) (FIG. 8 and FIG. 9)

4.1 Configuration and Operation 4.2 Effects 4.3 Modification Examples

5. Fifth Embodiment (an embodiment in which a light-quantity detectiondevice is disposed in an image display device) (FIG. 10)

5.1 Configuration and Operation

6. Sixth Embodiment (an embodiment in which a plurality of image displaydevices are provided, and light sources having a plurality of colorssources are caused to emit rays simultaneously) (FIG. 11 and FIG. 12)

6.1 Configuration 6.2 Light Emission Timing of Light Source Section andLight-Quantity Sampling Operation 6.3 Effects

7. Other embodiments

1. First Embodiment [1.1 Overall Configuration of Projection-TypeDisplay]

FIG. 1 illustrates an example of an overall configuration of aprojection-type display (a projector) according to a first embodiment ofthe disclosure.

This projection-type display includes an illuminator 1, an image displaydevice 21, a field lens 22, a beam splitter 23, and a projection lens24, as illustrated in FIG. 1. The illuminator 1 serves as a light sourceunit. The beam splitter 23 serves as a polarized-light separationdevice.

The illuminator 1 outputs illumination light L1 toward the beam splitter23. The illuminator 1 has a light source section and a plurality ofoptical members for illumination. The optical members generate theillumination light L1 on the basis of light from the light sourcesection, and guide the generated illumination light L1 to the imagedisplay device 21. As the light source section, there may be provided aplurality of light source sections that are disposed on differentoptical paths and emit rays of colors different from each other. Theilluminator 1 also has an optical-path synthesis device that synthesizesoptical paths of two or more light sources among the plurality of lightsource sections.

To be more specific, the illuminator 1 has a blue light source section10B a green light source section 10G, and a red light source section10R, as the plurality of light source sections. For example, the bluelight source section 10B, the green light source section 10G, and thered light source section 10R each include a laser light source. The bluelight source section 10B includes a blue laser 11B that may emit, forexample, blue light with a wavelength of about 450 nm, as a lightsource. The green light source section 10G includes a green laser 11Gthat may emit, for example, green light with a wavelength of about 520nm, as a light source. The red light source section 10R includes a redlaser 11R that may emit, for example, a red light with a wavelength ofabout 640 nm, as a light source.

The illuminator 1 further has a first coupling lens 12B, a secondcoupling lens 12G, a third coupling lens 12R, a drive optical device 14,a first dichroic prism 131, a second dichroic prism 132, a firstcondensing lens 141, a second condensing lens 142, and a fly-eye lens150, as the plurality of optical members for illumination.

The illuminator 1 further has a light quantity detector 40, a fourthcoupling lens 42, and a polarizing device 43. The light quantitydetector 40 includes a light-quantity detection device 41. Thelight-quantity detection device 41 may be configured of, for example, aphotodiode.

The second coupling lens 12G is a lens (a coupling lens) that collimatesthe green light outputted from the green laser 11G to couple thecollimated light (parallel light) to the first dichroic prism 131.Similarly, the first coupling lens 12B is a lens (a coupling lens) thatcollimates the blue light outputted from the blue laser 11B to couplethe collimated light to the first dichroic prism 131. Further, the thirdcoupling lens 12R is a lens (a coupling lens) that collimates the redlight outputted from the red laser 11R to couple the collimated light tothe second dichroic prism 132. It may be preferable that these couplinglenses 12R, 12G, and 12B collimate (to form parallel light of) therespective entering laser beams.

The first dichroic prism 131 and the second dichroic prism 132 are eachan optical-path synthesis device that synthesizes optical paths of twoor more light sources. The first dichroic prism 131 is a prism thatselectively reflects the green light entering through the secondcoupling lens 12G, while selectively allowing the blue light enteringthrough the first coupling lens 12B to pass therethrough. The seconddichroic prism 132 is a prism that selectively reflects most of the redlight entering through the third coupling lens 12R, while selectivelyallowing most of the blue light and the green light outputted from thefirst dichroic prism 131. Color synthesis (optical-path synthesis) forthe red light, the green light, and the blue light is thereby performed.

Further, the second dichroic prism 132 selectively reflects a portion ofthe red light entering through the third coupling lens 12R, toward thelight quantity detector 40, while selectively reflecting a portion ofthe blue light and the green light outputted from the first dichroicprism 131, toward the light quantity detector 40. The blue light, thegreen light, and the red light emitted from the plurality of lightsource sections 10B, 10G, and 10R thereby enter the light-quantitydetection device 41 of the light quantity detector 40 through thepolarizing device 43 and the fourth coupling lens 42in aspatially-common manner.

The drive optical device 14 is an optical device provided to reducespeckle noise and interference fringes in the illumination light L1. Thedrive optical device 14 is disposed on an optical path between the firstcondensing lens 141 and the second dichroic prism 132. For example, thedrive optical device 14 may be allowed to reduce the speckle noise andthe interference fringes in the illumination light L1, by changing astate of a bundle of passing rays by causing micro vibration in adirection along an optical axis or in a direction perpendicular to theoptical axis.

The fly-eye lens 150 is an optical member (an integrator) in which aplurality of lenses are two-dimensionally arranged on a substrate. Thefly-eye lens 150 spatially divides a bundle of entering rays accordingto an array of the plurality of lenses, and outputs light obtainedthereby. The fly-eye lens 150 is disposed on an optical path between thefirst condensing lens 141 and the second condensing lens 142. Thefly-eye lens 150 makes in-plane light quantity distribution of theillumination light L1 uniform.

The second condensing lens 142 is a lens provided to condense the lightoutputted from the fly-eye lens 150, and to output the condensed lighttoward the beam splitter 23 as the illumination light L1.

The beam splitter 23 is a polarized-light separation device thatseparates the entering light into a first polarized component (e.g.,S-polarized component) and a second polarized component (e.g.,P-polarized component), and outputs these polarized components indifferent directions. The beam splitter 23 selectively reflects aspecific first polarized component, while selectively allowing aspecific second polarized component to pass therethrough. For example,the beam splitter 23 may reflect much of the first polarized componentincluded in the entering illumination light L1, while allowing much ofthe second polarized component to pass therethrough.

For example, the image display device 21 may be a reflection-type liquidcrystal device such as a liquid crystal on silicon (LCOS). For example,the image display device 21 may modulate the first polarized componentincluded in the illumination light L1 entering through the field lens 22and the beam splitter 23, on the basis of image data. The image displaydevice 21 may also output the modulated light through the field lens 22and the beam splitter 23. The image display device 21 may output, forexample, the second polarized component, whose polarization state isturned from an entering state, as the modulated light. It is to be notedthat, in the image display device 21, it is possible to perform blackdisplay by returning the entering first polarized component to the beamsplitter 23 while maintaining a polarization state thereof as is.

The projection lens 24 projects the modulated light entering from theimage display device 21 through the beam splitter 23, onto a projectionplane of a screen 30. The projection lens 24 is a projection opticalsystem provided to project an image.

[1.2 Configuration and Operation of Control System] (1.2.1 ConfigurationExample of Control System)

FIG. 2 illustrates a configuration example of a control system of aprojection-type display. This projection-type display includes a maincontroller 90, an image-display-device control circuit 91, and a lightsource driver 92, as the control system. The main controller 90 includesa central processing unit (CPU).

The image-display-device control circuit 91 controls the image displaydevice 21, on the basis of an inputted image signal. Further, theimage-display-device control circuit 91 outputs a pulse-like lightemission timing signal based on the inputted image signal, to the maincontroller 90.

The main controller 90 controls light emission timings of the pluralityof light source sections 10B, 10G, and 10R through the light sourcedriver 92, in such a manner that the plurality of light source sections10B, 10G, and 10R each emit light at an appropriate timing, on the basisof a light emission timing signal. In particular, in the presentembodiment, the main controller 90 controls the plurality of lightsource sections 10B, 10G, and 10R in such a manner that light emissionperiods of the respective color rays temporally vary, as will bedescribed later.

Further, the main controller 90 performs feedback control of a lightquantity of the color ray emitted by each of the plurality of lightsource sections 10B, 10G, and 10R, through the light source driver 92,on the basis of a detection result of the light quantity detector 40. Inparticular, in the present embodiment, the main controller 90 performsthe feedback control of the light quantity, by controlling lightemission timings of the plurality of light source sections 10B, 10G, and10R and a gain of the light quantity detector 40, and measuring lightquantities of the respective plurality of color rays at differenttimings and with different gains, on the basis of the detection resultof the light quantity detector 40, as will be described later.

The light source driver 92 sets a current value of a driving current ofeach of the laser light sources, so as to bring a light quantity oflight emitted by the laser light source in each of the plurality oflight source sections 10B, 10G, and 10R, closer to a target lightquantity value specified by the main controller 90. The light sourcedriver 92 may have, for example, a drive transistor provided to controlon (light emission) and off (light extinction) of each of the laserlight sources. For example, it is possible to perform pulsed control ofon (light emission) and off (light extinction) of each of the laserlight sources in synchronization with the light emission timing signal,by inputting the above-described pulse-like light emission timing signalas a gate signal of the drive transistor.

(1.2.2 Light Emission Timing of Light Source Section and Light-QuantitySampling Operation)

FIG. 3 illustrates an example of each of light emission timings of theplurality of light source sections 10B, 10G, and 10R, and light-quantitysampling operation in the light quantity detector 40, in the presentembodiment.

It is to be noted that FIG. 3 illustrates a light emission timing signalof the red light, a light emission timing signal of the green light, anda light emission timing signal of the blue light, in order from top. Ahorizontal axis indicates time, and a vertical axis indicates a signalvalue, of the light emission timing signal in FIG. 3. Periods in whichthe light emission timing signals of the respective color rays are highare light emission periods Tr1, Tg1, and Tb1 of the respective colorrays, and periods in which the light emission timing signals of therespective color rays are low are light extinguished periods Tr0, Tg0,and Tb0 of the respective color rays.

Further, a lowermost part of FIG. 3 illustrates a set value of a gain ofthe light quantity detector 40, in which a vertical axis indicates thetime, and a horizontal axis indicates a gain value. Gab indicates a gainvalue for the blue light, Gag indicates a gain value for the greenlight, and Gar indicates a gain value for the red light. Sb indicates adetection value (a sampling value) of a light quantity of the bluelight, Sg indicates a sampling value of a light quantity of the greenlight, and Sr indicates a sampling value of a light quantity of the redlight, obtained by the light quantity detector 40.

The laser light sources of the respective light source sections 10B,10G, and 10R emit rays at timings according to the light emission timingsignals of the blue light, the green light, and the red light, asillustrated in FIG. 3. Each of the laser light sources also emits a raywith a current value set by the light source driver 92. The lightquantity of each of the laser light sources is converted into a voltagevalue by the light-quantity detection device 41 of the light quantitydetector 40. The voltage value is subjected to AD conversion by the maincontroller 90, and fed back to the light emission quantity of each ofthe laser light sources at and after the next light emission timing.

Meanwhile, most light not allocated to the light quantity detector 40enters the image display device 21. In the image display device 21, areflectance of each pixel of each of the colors is set by theimage-display-device control circuit 91, at a timing matching with thelight emission timing of each of the colors, according to the imagesignal. Image information of each of the colors is projected onto thescreen 30 by the image display device 21 in a time series, and therebyan image is displayed on the screen 30.

The main controller 90 sets the gain value Gar for the red light as thegain value of the light quantity detector 40, at a timing when the lightemission timing signal of the red light becomes high, as illustrated inFIG. 3. The gain value Gar for the red light is set in such a mannerthat a value which the sampling value Sr of the red light may take inthe light quantity detector 40 sufficiently falls within a detectionrange in the light quantity detector 40. The main controller 90 thenacquires a detection value of the red light generated by the lightquantity detector 40.

Similarly, the main controller 90 sets the gain value Gag for the greenlight as the gain value of the light quantity detector 40, at a timingwhen the light emission timing signal of the green light becomes high.The gain value Gag for the green light is set in such a manner that avalue which the sampling value Sg of the green light may take in thelight quantity detector 40 sufficiently falls within the detection rangein the light quantity detector 40. The main controller 90 then acquiresa detection value of the green light generated by the light quantitydetector 40. Similar operation is performed for the blue light.Afterward, these operations are repeated each time the light emissiontiming signal changes.

This optimizes the gain in such a manner the light quantity of the redlight becomes a maximum value falling within the detection range of thelight quantity detector 40, in a period in which the light emissiontiming signal of the red light is high and the light quantity of the redlight is sampled. This makes it possible to obtain the light quantityvalue of the red light with sufficient resolution. This is applicable tothe green light and the blue light.

FIG. 4 illustrates an example of a flow of the light-quantity samplingoperation described above.

First, the main controller 90 determines whether it is the lightemission period Tr1 of the red light, on the basis of the light emissiontiming signal (step S11). When it is not the light emission period Tr1of the red light (N in step S11), the operation proceeds to step S13.When it is the light emission period Tr1 of the red light (Y in stepS11), the main controller 90 sets the gain value Gar optimal for the redlight as the gain of the light quantity detector 40 (step S12), and thenproceeds to step S13.

In step S13, the main controller 90 determines whether it is the lightemission period Tg1 of the green light, on the basis of the lightemission timing signal (step S13). When it is not the light emissionperiod Tg1 of the green light (N in step S13), the operation proceeds tostep S15. When it is the light emission period Tg1 of the green light (Yin step S13), the main controller 90 sets the gain value Gag optimal forthe green light as the gain of the light quantity detector 40 (stepS14), and then proceeds to step S15.

In step S15, the main controller 90 determines whether it is the lightemission period Tb1 of the blue light, on the basis of the lightemission timing signal (step S15). When it is not the light emissionperiod Tb1 of the blue light (N in step S15), the operation returns tostep S11. When it is the light emission period Tb1 of the blue light (Yin step S15), the main controller 90 sets the gain value Gab optimal forthe blue light as the gain of the light quantity detector 40 (step S16),and then returns to step S11.

[1.3 Effects]

As described above, according to the present embodiment, the pluralityof color rays are allowed to enter the light quantity detector 40 in aspatially-common manner, and the light quantities of the respectivecolor rays are measured at different timings with different gains. Thisallows the one light quantity detector 40 to measure the light quantityof each of the plurality of color rays precisely. According to thepresent embodiment, the gain optimal for each of the colors is set,which makes it possible to use a dynamic range of the light quantitydetector 40 sufficiently. It is therefore possible to obtain a samplingvalue of sufficient resolution. This makes it possible to performprecise power control of the light source, and suppress occurrence of aflicker phenomenon to be caused by the light source.

(Advantage of Changing Gain for Each Color)

An advantage of changing the gain for each of the colors is specificallyas follows. For example, when the wavelength of the red light is 780 nm,the wavelength of the green light is 650 nm, and the wavelength of theblue light is 405 nm, sensitivity of the light-quantity detection device41 for the same light quantity may be, for example,R:G:B=7.15:7.52:4.70, as a typical value. In this case, a differencebetween the green with the largest value and the blue with the smallestvalue is 1.6 times. It is therefore necessary to adjust the sensitivityto the blue light when the gain is not changed, and resolution of theblue light results in 1/1.6. In other words, only a gain that is 1.6times rougher than that of the green light is settable for the bluelight.

It is to be noted that the effect described in the specification is amere example without being limitative, and other effect may be produced.This is also applicable to the following other embodiments.

2. Second Embodiment

Next, a second embodiment of the disclosure will be described. In thefollowing, description of a part similar to the first embodiment interms of configuration and action will be omitted as appropriate.

[2.1 Configuration and Operation]

In the first embodiment, the description is provided using the examplein which each of the plurality of light source sections 10B, 10G, and10R has one laser light source. However, at least one predeterminedlight source section among the plurality of light source sections 10B,10G, and 10R may have a plurality of light sources that emitpredetermined color light of the same color. Further, light quantitiesof the rays of the respective plurality of light sources may be measuredat timings different from each other, by extinguishing at least onelight source among the plurality of light sources for a predeterminedperiod, in a light emission period of the predetermined color light inthe predetermined light source section.

In the present embodiment, there will be described an example case wherethe red light source section 10R is provided as the predetermined lightsource section, and the red light source section 10R has two laser lightsources (a first red laser 11R1 and a second red laser 11R2) that emitthe red light as the predetermined color light.

It is to be noted that, in the present embodiment, an overallconfiguration of a projection-type display (a projector) and aconfiguration of a control system may be substantially similar to thoseillustrated in FIG. 1 and FIG. 2, except for the configuration of thered light source section 10R.

FIG. 5 illustrates an example of each of light emission timings of thelight source section 10R, and light-quantity sampling operation in thelight quantity detector 40, in the present embodiment.

It is to be noted that FIG. 5 illustrates a light emission timing signalof the red light of the light source section 10R as a whole, a lightemission timing signal of the first red laser 11R1 in the red lightsource section 10R, and a light emission timing signal of the second redlaser 11R2 in the red light source section 10R, in order from top. Ahorizontal axis indicates time, and a vertical axis indicates a signalvalue, of the light emission timing signal in FIG. 5. A period in whichthe light emission timing signal is high is each of light emissionperiods Tr11 and Tr12, and a period in which the light emission timingsignal is low is a light extinguished period Tr0. Sr1 indicates asampling value of a light quantity of the first red laser 11R1, and Sr2indicates a sampling value of a light quantity of the second red laser11R2.

It is conceivable that, when the red light source section 10R has thetwo laser light sources, feedback control may be performed in such amanner that the light quantity detector 40 obtains a value representinga total of light quantities of the two laser light sources, and a valuedetermined by dividing the obtained value by 2 may be fed back as asampling value of each of the light quantities of the two laser lightsources. However, even if the two laser light sources are of the samecolor, same light quantities may not be necessarily obtained because of,for example, variety of individuals, even when driving currents of thesame current value are supplied to the two laser light sources. It istherefore hardly conceivable that the sampling values of the lightquantities of the two laser light sources may also become identical. Toset an appropriate current value for each of the laser light sources, asampling value of a light quantity of each of the two laser lightsources is necessary.

For this reason, in the present embodiment, the light quantities of raysemitted by the two laser light sources are measured at the timingsdifferent from each other, by extinguishing one of the two laser lightsources for a predetermined period, in the light emission periods Tr11and Tr12 as a whole of the red light source section 10R, as illustratedin FIG. 5. In the example in FIG. 5, the sampling value Sr2 of the lightquantity of the second red laser 11R2 is obtained by extinguishing thefirst red laser 11R1 for a predetermined period, in the first lightemission period Tr11 of the red light. Subsequently, the sampling valueSr1 of the light quantity of the first red laser 11R1 is obtained byextinguishing the second red laser 11R2 for a predetermined period, inthe second light emission period Tr12 of the red light.

It is to be noted that, when the time during which the laser lightsource is extinguished for sampling is 1000 μs or more, on/off operationof the laser light source is visible, which leads to a flickerphenomenon. To prevent this, the time during which the laser lightsource is extinguished for sampling may be preferably 1000 μs or less.

In addition, in the above description, the red light source section 10Ris taken as an example. However, it is possible to perform similarcontrol in a case where the blue light source section 10B and the greenlight source section 10G each have a plurality of light sources.

[2.2 Effects]

According to the present embodiment, it is possible to obtain a samplingvalue for each individual even if a plurality of light sources of thesame color are present. It is therefore possible to perform precisefeedback control for each of the light sources.

(Advantage of Separately Obtaining Sampling Values of Light Sources ofSame Color)

Advantages of separately obtaining sampling values of the plurality oflight sources of the same color are specifically as follows.

(1) Assume that there are two light sources of the same color, and lightquantities of the respective light sources when a certain current valueis fed are A and B. In this case, a light quantity when collectivelyobtained is A+B, and a current value is set for each of the lightsources as a light quantity of (A+B)/2. However, if IL properties of therespective light sources are different, actual light quantities in therespective light sources are different even if the same current value isset. One with a larger light quantity emits light beyond an upper limit,and thus may be broken early.

(2) When there are two light sources of the same color, and one of thelight sources is broken, the light quantity as a whole is halved.However, when the light quantities are simultaneously obtained, it maybe misunderstood that each of the light quantities of both of the lightsources is halved. In this case, light may be emitted until a limitcurrent value is reached, and thereby the other light source which isnot broken may be broken. If the sampling values are separatelyobtained, the light quantity of each of the two light sources isrecognized, and therefore, the above-described incident does not occur.In addition, it is possible to reduce power consumption, by addingprocessing of stopping the light emission of the broken one.

(3) In the projector in which the plurality of light sources of the samecolor are disposed, it is not necessary to make projection ranges of therespective light sources equal if light quantities of the respectivelight sources are equal. It is possible to provide such a design thateach of the light sources is in charge of a corresponding projectionrange. However, such a design is not acceptable if the light quantitiesof the respective light sources are not equal. In other words, luminanceunevenness appears in a projection range, which renders this projectoruseless as a projector.

According to the present embodiment, it is possible to make the lightquantities of the respective light sources equal by separately obtainingthe sampling values of the light sources of the same color. It istherefore possible to achieve the above-described design flexibility.

3. Third Embodiment

Next, a third embodiment of the disclosure will be described. In thefollowing, description of a part similar to the first embodiment or thesecond embodiment in terms of configuration and action will be omittedas appropriate.

[3.1 Configuration and Operation]

In the second embodiment, the example case where the two light sourcesof the same color are provided in the one light source section isdescribed. However, in the present embodiment, an example case wherethree or more light sources of the same color are provided in one lightsource section will be described. The main controller 90 may calculate alight quantity of light emitted by specific one light source, on thebasis of a difference between a detection result of the light quantitydetector 40 in a case where all of the plurality of light sources emitlight and a detection result of the light quantity detector 40 in a casewhere the specific one light source among the plurality of light sourcesis extinguished.

In the present embodiment, there will be described an example case wherethe red light source section 10R is provided as the predetermined lightsource section, and the red light source section 10R has three laserlight sources (the first red laser 11R1, the second red laser 11R2, anda third red laser 11R3) that emit the red light as the predeterminedcolor light.

It is to be noted that, in the present embodiment, an overallconfiguration of a projection-type display (a projector) and aconfiguration of a control system may be substantially similar to thoseillustrated in FIG. 1 and FIG. 2, except for the configuration of thered light source section 10R.

FIG. 6 illustrates an example of each of light emission timings of thelight source section 10R, and light-quantity sampling operation in thelight quantity detector 40, in the present embodiment.

It is to be noted that FIG. 6 illustrates a light emission timing signalof the red light of the light source section 10R as a whole, a lightemission timing signal of the first red laser 11R1 in the red lightsource section 10R, a light emission timing signal of the second redlaser 11R2 in the red light source section 10R, and a light emissiontiming signal of the third red laser 11R3 in the red light sourcesection 10R, in order from top. A horizontal axis indicates time, and avertical axis indicates a signal value, of the light emission timingsignal in FIG. 6. A period in which the light emission timing signal ishigh is each of light emission periods Tr11 and Tr12, and a period inwhich the light emission timing signal is low is a light extinguishedperiod Tr0. Sr1 indicates a sampling value of a light quantity of thefirst red laser 11R1, and Sr2 indicates a sampling value of a lightquantity of the second red laser 11R2.

When the three or more laser light sources of the same color arepresent, one laser light source among the three laser light sources isextinguished for a predetermined period, in the light emission periodsTr11 and Tr12 of the red light source section 10R as a whole, asillustrated in FIG. 6. Further, a sampling value of a light quantityobtained at this time is subtracted from a sampling value of a lightquantity when all the three laser light sources emit light. This makesit possible to calculate a sampling value of a light quantity of theextinguished one laser light source.

In the example in FIG. 6, the first red laser 11R1 is extinguished forthe predetermined period, in the first light emission period Tr11 of thered light. Further, the sampling value of the light quantity obtainedwhen the first red laser 11R1 is extinguished is subtracted from thesampling value of the light quantity obtained when all the three laserlight sources emit light in the first light emission period Tr11. Thesampling value Sr1 of the light quantity of the first red laser 11R1 isthereby calculated.

Subsequently, the second red laser 11R2 is extinguished for thepredetermined period, in the second light emission period Tr12 of thered light. Further, the sampling value of the light quantity obtainedwhen the second red laser 11R2 is extinguished is subtracted from thesampling value of the light quantity obtained when all the three laserlight sources emit light in the second light emission period Tr12. Thesampling value Sr2 of the light quantity of the second red laser 11R2 isthereby calculated.

It is to be noted that the period during which the laser light source isextinguished for sampling may be preferably 1000 μs or less, as with thesecond embodiment.

In addition, in the above description, the red light source section 10Ris described as an example. However, it is possible to perform similarcontrol when the blue light source section 10B and the green lightsource section 10G each have three or more light sources.

[3.2 Effects]

According to the present embodiment, it is possible to minimize thenumber of laser light sources to be extinguished for sampling of a lightquantity. If only one laser light source is extinguished when thesampling value of the light quantity of each of three or more laserlight sources is obtained, it is possible to obtain the sampling valueof the light quantity of the one laser light source. It is thereforepossible to minimize a decline in light quantity in a case where thelaser light source is extinguished in sampling.

[3.3 Modification Example]

It is to be noted that, for more accurate sampling, only a laser lightsource targeted for sampling of a light quantity may be caused to emitlight, and all other laser light sources may be extinguished. FIG. 7illustrates an example of each of light emission timing of the lightsource section 10R, and light-quantity sampling operation in the lightquantity detector 40, when such light emission control is performed.

In the example in FIG. 7, the first red laser 11R1 and the second redlaser 11R2 are extinguished for a predetermined period, in the firstlight emission period Tr11 of the red light. The sampling value Sr2 ofthe light quantity of the second red laser 11R2 is thereby obtaineddirectly.

Subsequently, the second red laser 11R2 and the third red laser 11R3 areextinguished for a predetermined period, in the second light emissionperiod Tr12 of the red light. The sampling value Sr1 of the lightquantity of the first red laser 11R1 is thereby obtained directly.

4. Fourth Embodiment

Next, a fourth embodiment of the disclosure will be described. In thefollowing, description of a part similar to the first embodiment to thethird embodiment in terms of configuration and action will be omitted asappropriate.

4.1 Configuration and Operation

In the second and third embodiments, there is described the example inwhich the plurality of light sources of the same color are provided inone light source section, and the light quantity of each of the lightsources is measured once within one light emission period. However, thelight quantity of each of the light sources may be measured a pluralityof times over a plurality of light emission periods. In the presentembodiment, the main controller 90 extinguishes at least one lightsource among a plurality of light sources for a predetermined period, ineach of a plurality of light emission periods of predetermined colorlight in a predetermined light source section. A light quantity of lightemitted by each of the plurality of light sources is thereby measured aplurality of times at different timings over a plurality of lightemission periods.

It is to be noted that, in the present embodiment, an overallconfiguration of a projection-type display (a projector) and aconfiguration of a control system may be substantially similar to thoseillustrated in FIG. 1 and FIG. 2, except for the configuration of thered light source section 10R.

In the second and third embodiments, only a value in a case where alightquantity sampling segment is a certain moment within one light emissionperiod of a certain color is obtained. However, in a laser light source,sampling values may involve variations due to a phenomenon called amode-hop. It is conceivable that when a sampled value takes a value atthis phenomenon by chance, a flicker phenomenon may occur if feedback isperformed on the basis of such a value. However, if sampling isperformed a plurality of times within one light emission period, thenumber of times the laser light source is extinguished in a short periodmay increase, which may cause a change in light quantity in a shortperiod, leading to a flicker phenomenon. Alternatively, if the number oftimes the laser light source is extinguished for sampling is large, anoverall light quantity may decrease, which may decrease performance ofbrightness of a projector. To address such an issue, sampling may beperformed a plurality of times for one laser light source over aplurality of light emission periods (a plurality of frames).

FIG. 8 illustrates an example of each of light emission timings of thered light source section 10R, and light-quantity sampling operation inthe light quantity detector 40, in the present embodiment. In FIG. 8,there will be described an example case where the red light sourcesection 10R is provided as the predetermined light source section, andthe red light source section 10R has two laser light sources (the firstred laser 11R1 and the second red laser 11R2) that emit the red light,as with the second embodiment.

In the example in FIG. 8, in the first light emission period Tr11 of thered light, the first red laser 11R1 is extinguished for a predeterminedperiod, and a first sampling value A of a light quantity of the secondred laser 11R2 is thereby obtained. Subsequently, in the second lightemission period Tr12 of the red light, the first red laser 11R1 isextinguished for a predetermined period, and a second sampling value Bof a light quantity of the second red laser 11R2 is thereby obtained. Itis possible to calculate the sampling value Sr2 of the light quantity ofthe second red laser 11R2, with (A+B)/2.

In this way, one laser light source is extinguished over a plurality oflight emission periods, and a sum of the sampled values is divided bythe number of sampling times. This makes it possible to average thesampling values of the plurality of light emission periods. The numberof sampling times is two in the example in FIG. 8, but may be any numberof two or more.

It is to be noted that the period during which the laser light source isextinguished for sampling may be preferably 1000 μs or less, as with thesecond embodiment.

In addition, in the above description, the red light source section 10Ris described as an example. However, it is possible to perform similarcontrol when the blue light source section 10B and the green lightsource section 10G each have a plurality of light sources.

4.2 Effects

According to the present embodiment, it is possible to minimize thelight quantity that decreases due to extinguishing of the light sourcein sampling, by sampling the light quantity over the plurality of lightemission periods (the plurality of frames).

4.3 Modification Examples

In the operation examples illustrated in FIG. 5 to FIG. 8, the lightquantity within one light emission period (one frame) is sampled only byperforming sampling for any one of the laser light sources. However,sampling for a plurality of laser light sources of the same color may beperformed within the same frame, if sampling timings do not overlap.Further, sampling may be performed a plurality of times for the samelaser light source within one light emission period.

Furthermore, there may be adopted a mechanism in which a technique ofperforming sampling over a plurality of frames, a technique ofperforming sampling a plurality of times within one frame, and atechnique of performing sampling for different laser light sources aremixed to attain the specified number of sampling times.

In addition, when sampling is performed over a plurality of frames, itis not necessary to wait for sampling operation of other laser lightsources (for example, the second red laser 11R2 or the third red laser11R3) until the end of the number of sampling times for certain onelaser light source (for example, the first red laser 11R1). Sampling maybe performed for each of the laser light sources alternately. Moreover,the time to perform sampling for each of the laser light sources may notbe predetermined, and sampling data may be obtained in a temporallyirregular manner.

Meanwhile, values of light quantities may involve variations even withinthe same light emission period, due to a heat sag or a mode-hop in thelaser light source. For this reason, it is also effective to obtain avalue by temporally shifting a sampling position, when sampling isperformed over a plural frames, as illustrated in FIG. 9. The number oftimes is three in the example in FIG. 9. However, the number of timesmay be any number of two or more. In this case as well, as describedabove, a technique of performing sampling over a plurality of frames, atechnique of performing sampling a plurality of times within the sameframe, and a technique of performing sampling for other laser lightsource may be mixed. In other words, various techniques may be freelymixed.

In the example in FIG. 9, in the first light emission period Tr11 of thered light, the first red laser 11R1 is extinguished for a predeterminedperiod, and a first sampling value A of a light quantity of the secondred laser 11R2 is thereby obtained. Subsequently, in the second lightemission period Tr12 of the red light, the first red laser 11R1 isextinguished for a predetermined period, and a second sampling value Bof a light quantity of the second red laser 11R2 is thereby obtained.Subsequently, in a second light emission period Tr13 of the red light,the first red laser 11R1 is extinguished for a predetermined period, anda third sampling value C of a light quantity of the second red laser11R2 is thereby obtained. In addition, in each of the first to thirdlight emission periods, timings for extinguishing the first red laser11R1 are different. It is possible to calculate the sampling value Sr2of the light quantity of the second red laser 11R2, with (A+B+C)/3.

In this way, when sampling is performed over a plurality of lightemission periods, the timing of performing sampling within each of thelight emission periods is varied, so that it is possible to obtain asampling value within each of the light emission periods in atemporally-balanced manner.

5. Fifth Embodiment

Next, a fifth embodiment of the disclosure will be described. In thefollowing, description of a part similar to the first embodiment to thefourth embodiment in terms of configuration and action will be omittedas appropriate.

[5.1 Configuration and Operation]

In the configuration example illustrated in FIG. 1, the example in whichthe light quantity detector 40 including the light-quantity detectiondevice 41 is disposed in the illuminator 1 is described. However, thelight quantity detector 40 may be configured of a plurality oflight-quantity detection devices 41 embedded in the image display device21, as illustrated in, for example, FIG. 10. The light-quantitydetection device 41 may be a photo diode (PD).

In other words, without being disposed at a position close to the lightsource as illustrated in FIG. 1, the light quantity detector 40 may beconfigured in such a manner that the plurality of light-quantitydetection devices 41 are embedded in upper and lower regions (a firstdetection region 40A and a second detection region 40B) outside adisplay region 21A of the image display device 21, as illustrated in,for example, FIG. 10. A design is provided beforehand to irradiate thefirst detection region 40A and the second detection region 40B as wellwith light from the light source.

In such a configuration as well, it is possible to change the gain ofthe light quantity detector 40 for each of the color rays. For example,it is possible to control the gain, with the number of thelight-quantity detection devices 41 to be used for light quantitydetection. For example, it is possible to obtain effects similar tothose in a case in which the gain is a half if the number of thelight-quantity detection devices 41 to be used for light quantitydetection is a half, and a case in which the gain is a quarter if thenumber of the light-quantity detection devices 41 to be used for lightquantity detection is a quarter.

In addition, for example, assume that the light-quantity detectiondevices 41 are numbered 1, 2, 3, 4, 5, . . . from left, to eliminate aninfluence of in-plane light quantity unevenness when the number isdecreased. In this case, only the light-quantity detection devices 41numbered 1, 3, 5, 7, 9, . . . are used to decrease the number to a half,whereas only the light-quantity detection devices 41 numbered 1, 5, 9, .. . are used to decrease the number to a quarter. This makes itdifficult to receive the influence of the in-plane light quantityunevenness

6. Sixth Embodiment

Next, a sixth embodiment of the disclosure will be described. In thefollowing, description of a part similar to the first embodiment to thefifth embodiment in terms of configuration and action will be omitted asappropriate.

[6.1 Configuration]

FIG. 11 illustrates an example of an overall configuration of aprojection-type display according to the sixth embodiment of thedisclosure. This projection-type display includes the projection lens24, a lens section 102, a dichroic color separation filter 103, a beamsplitter 104 b, a beam splitter 104 g, a beam splitter 104 r, a dichroicprism 106, a total reflection mirror 108, and a total reflection mirror109.

This projection-type display also includes three image display devicesof an image display device 21B for blue, an image display device 21G forgreen, and an image display device 21R for red, in place of the oneimage display device 21 in FIG. 1.

In the configuration example in FIG. 1, the plurality of light sourcesections 10B, 10G, and 10R disposed on the different optical paths andthe one image display device 21 are provided, and the plurality of lightsource sections 10B, 10G, and 10R apply the respective color rays atdifferent timings to the one image display device 21. In contrast, inthe configuration example in FIG. 11, the plurality of light sourcesections 10B, 10G, and 10R are integrally disposed on the same opticalpath, and the plurality of light source sections 10B, 10G, and 10Rsimultaneously emit rays when an image is displayed. The correspondingcolor ray is emitted to each of the image display devices 21B, 21G, and21R. Images of the respective colors formed by the image display devices21B, 21G, and 21R are synthesized with the dichroic prism 106 andprojected onto the screen 30 through the projection lens 24.

The light quantity detector 40 may be disposed, for example, behind thedichroic color separation filter 103. The blue light, the green light,and the red light emitted from the plurality of light source sections10B, 10G, and 10R enter the light quantity detector 40, as temporallyand spatially common light.

In the present embodiment, a configuration of a control system of theprojection-type display may include the main controller 90, theimage-display-device control circuit 91, and the light source driver 92,substantially similarly to that illustrated in FIG. 2. In the presentembodiment, the image-display-device control circuit 91 controls each ofthe image display devices 21B, 21G, and 21R, on the basis of an inputtedimage signal.

[6. 2 Light Emission Timing of Light Source Section and Light-QuantitySampling Operation]

Light emission timing of the light source section and light-quantitysampling operation may be performed, for example, as illustrated in FIG.12. FIG. 12 illustrates a light emission timing signal of the red light,a light emission timing signal of the green light, and a light emissiontiming signal of the blue light, in order from top. A horizontal axisindicates time, and a vertical axis indicates a signal value, of thelight emission timing signal in FIG. 12. Periods in which the lightemission timing signals of the respective color rays are high are lightemission periods Tr1, Tg1, and Tb1 of the respective color rays, andperiods in which the light emission timing signals of the respectivecolor rays are low are light extinguished periods Tr0, Tg0, and Tb0 ofthe respective color rays. Sb indicates a detection value (a samplingvalue) of a light quantity of the blue light, Sg indicates a samplingvalue for the green light, and Sr indicates a sampling value for the redlight, obtained by the light quantity detector 40.

In the present embodiment, it is possible to sample the light quantityof each of the light source sections by a technique similar to thetechnique illustrated in FIG. 6.

In the present embodiment, the main controller 90 causes the pluralityof light source sections 10B, 10G, and 10R to emit rays simultaneously,in a period except for a period for measurement of the light quantity ofeach of the color rays. In the period for measurement of the lightquantity of each of the color rays, only one light source section thatemits a color ray to be measured among the plurality of light sourcesections 10B, 10G, and 10R is extinguished for a predetermined period.The main controller 90 calculates the light quantity of the ray emittedby the one light source section, on the basis of a difference between adetection result of the light quantity detector 40 in a case where allthe plurality of light source sections 10B, 10G, and 10R emit light anda detection result of the light quantity detector 40 in a case whereonly the one light source section is extinguished.

In the example in FIG. 12, first, the red light source section 10R isextinguished for a predetermined period. A sampling value of a lightquantity obtained when the red light source section 10R is extinguishedis then subtracted from a sampling value of a light quantity obtainedwhen all the plurality of light source sections 10B, 10G, and 10R emitlight, and the sampling value Sr of a light quantity of the red light isthereby calculated.

Subsequently, the green light source section 10G is extinguished for apredetermined period. A sampling value of a light quantity obtained whenthe green light source section 10G is extinguished is then subtractedfrom a sampling value of a light quantity obtained when all theplurality of light source sections 10B, 10G, and 10R emit light, and thesampling value Sg of a light quantity of the green light is therebycalculated. Subsequently, with a similar technique, the sampling valueSb of a light quantity of the blue light is calculated by extinguishingthe blue light source section 10B for a predetermined period.

It is to be noted that the period during which the laser light source isextinguished for sampling may be preferably 1000 μs or less, as with thesecond embodiment.

In addition, in the present embodiment as well, the gain of the lightquantity detector 40 may be changed for each of the color rays,according to a timing of obtaining a sampling value of a light quantityof each of the color rays.

[6.3 Effects]

According to the present embodiment, it is possible to precisely measurelight quantities of the plurality of color rays with the one lightquantity detector 40, by allowing the plurality of color rays to enterthe one light quantity detector 40 in a spatially-common manner, andextinguishing only one light source section that emits a color ray to bemeasured among the plurality of light source sections for apredetermined period, in a so-called three-plate projection-typedisplay.

7. Other Embodiments

The technology of the disclosure is not limited to the description ofeach of the above-described embodiments, and it is possible to implementvarious modifications. For example, the technology may adopt thefollowing configurations.

(1)

A light source unit including:

a plurality of light source sections that emit rays of colors differentfrom each other;

a light quantity detector that receives the rays of colors emitted bythe plurality of light source sections in a spatially-common manner; and

a controller that controls a light emission timing of each of theplurality of light source sections and a gain of the light quantitydetector, and measures light quantities of the respective rays of colorsat different timings and with different gains on the basis of adetection result of the light quantity detector.

(2)

The light source unit according to (1), in which the controller controlsthe plurality of light source sections to cause light emission periodsof the respective rays of colors to be temporally different from eachother.

(3)

The light source unit according to (2), in which

among the plurality of light source sections, at least one predeterminedlight source section has a plurality of light sources that emit rays ofa predetermined same color, and

the controller measures light quantities of rays emitted by therespective plurality of light sources at timings different from eachother, by extinguishing at least one light source among the plurality oflight sources for a predetermined period, within a light emission periodof the ray of the predetermined color in the predetermined light sourcesection.

(4)

The light source unit according to (3), in which

the predetermined light source section has three or more light sourcesthat emit rays of a predetermined same color, and

the controller calculates, on the basis of a difference between adetection result of the light quantity detector upon light emission ofall of the plurality of light sources and a detection result of thelight quantity detector upon extinguishment of a specific one lightsource among the plurality of light sources, a light quantity of a rayemitted by the specific one light source.

(5)

The light source unit according to (3), in which, in each of a pluralityof light emission periods of the ray of the predetermined color in thepredetermined light source section, the controller extinguishes at leastone light source among the plurality of light sources for apredetermined period, and thereby measures the light quantity of the rayemitted by each of the plurality of light sources a plurality of timesat timings different from each other, over the plurality of lightemission periods.

(6)

The light source unit according to (5), in which the controller causestimings of extinguishing the at least one light source to be differentfrom each other between the respective light emission periods.

(7)

The light source unit according to any one of (3) to (6), in which, inthe light emission period, the period during which the at least onelight source is extinguished is 1000 μs or less.

(8)

The light source unit according to (1), in which the controller causesthe plurality of light source sections to emit the rays simultaneously,in a period except for a period in which the measurement of the lightquantity of each of the rays of colors is performed, and extinguishesonly one light source section that emits a ray of color to be measuredamong the plurality of light source sections for a predetermined period,in the period in which the measurement of the light quantity of each ofthe rays of colors is performed.

(9)

The light source unit according to (8), in which the controllercalculates, on the basis of a difference between a detection result ofthe light quantity detector upon light emission of all of the pluralityof light source sections and a detection result of the light quantitydetector upon extinguishment of only the one light source section, alight quantity of a ray emitted by the one light source section.

(10)

The light source unit according to (8) or (9), in which the periodduring which the one light source section is extinguished is 1000 μs orless.

(11)

A light source unit including:

a plurality of light source sections that emit rays of colors differentfrom each other;

a light quantity detector that receives the rays of colors emitted bythe plurality of light source sections in a spatially-common manner; and

a controller that controls a light emission timing of each of theplurality of light source sections, and measures light quantities of therespective rays of colors at different timings on the basis of adetection result of the light quantity detector, in which

the controller causes the plurality of light source sections to emit therays simultaneously, in a period except for a period in which themeasurement of the light quantity of each of the rays of colors isperformed, and extinguishes only one light source section that emits theray of color to be measured among the plurality of light source sectionsfor a predetermined period, in the period in which the measurement ofthe light quantity of each of the rays of colors is performed.

(12)

The light source unit according to (11), in which the controllercalculates, on the basis of a difference between a detection result ofthe light quantity detector upon light emission of all of the pluralityof light source sections and a detection result of the light quantitydetector upon extinguishment of only the one light source section, alight quantity of the ray emitted by the one light source section.

(13)

The light source unit according to (11) or (12), in which the periodduring which the one light source section is extinguished is 1000 μs orless.

(14)

A projection-type display including: a plurality of light sourcesections that emit rays of colors different from each other;

at least one image display device that modulates the rays of colorsemitted by the plurality of light source sections on the basis of animage signal, and outputs the modulated rays;

a light quantity detector that receives the rays of colors in aspatially-common manner; and

a controller that controls a light emission timing of each of theplurality of light source sections and a gain of the light quantitydetector, and measures light quantities of the respective rays of colorsat different timings and with different gains on the basis of adetection result of the light quantity detector.

(15)

A projection-type display including: a plurality of light sourcesections that emit rays of colors different from each other;

a plurality of image display devices that modulate the respective raysof colors emitted by the plurality of light source sections, on thebasis of an image signal, and output the respective modulated rays forthe respective rays of colors;

a light quantity detector that receives the rays of colors in aspatially-common manner; and

a controller that controls a light emission timing of each of theplurality of light source sections, and measures light quantities of therespective rays of colors at different timings on the basis of adetection result of the light quantity detector, in which

the controller causes the plurality of light source sections to emit therays simultaneously, in a period except for a period in which themeasurement of the light quantity of each of the rays of colors isperformed, and extinguishes only one light source section that emits aray of color to be measured among the plurality of light source sectionsfor a predetermined period, in the period in which the measurement ofthe light quantity of each of the rays of colors is performed.

The present application is based on and claims priority from JapanesePatent Application No. 2014-237818 filed in the Japan Patent Office onNov. 25, 2014, the entire contents of which is hereby incorporated byreference.

It should be understood by those skilled in the art that variousmodifications, combinations, sub-combinations and alterations may occurdepending on design requirements and other factors insofar as they arewithin the scope of the appended claims or the equivalents thereof.

What is claimed is:
 1. A projector, comprising: at least one lightsource section of a plurality of light source sections configured toemit lights of colors different from each other; at least one imagedisplay device; a light quantity detector configured to receive each ofthe emitted lights of colors; and a control section configured to:control a light emission timing of each of the plurality of light sourcesections and a gain of the light quantity detector; and measure lightquantities of the respective lights of colors at different timings andwith different gains based on a detection result of the light quantitydetector.
 2. The projector according to claim 1, wherein the at leastone light source section of a plurality of light source sections includea first light source and a second light source that are configured toemit the lights of a same color of a plurality of colors.
 3. Theprojector according to claim 2, wherein the control section controls alight emission timing of each of the first light source and the secondlight source.
 4. The projector according to claim 3, wherein the controlsection measures, at first different timings, a first light quantity ofthe light emitted by one of the first light source or the second lightsource, based on a detection result of the light quantity detector. 5.The projector according to claim 4, wherein the control sectionextinguishes other of the first light source or the second light sourcefor a first time period for the measurement.
 6. The projector accordingto claim 5, wherein the first time period is less than a light emissionperiod of the lights emitted by each of the first light source and thesecond light source.
 7. The projector according to claim 6, wherein thecontrol section is further configured to measure, at the first differenttimings, a second light quantity of the lights emitted by the other ofthe first light source or the second light source, based on the one ofthe first light source or the second light source that is extinguishedfor the first time period.
 8. The projector according to claim 1,wherein the at least one image display device modulates the lights ofcolors emitted by the plurality of light source sections on a basis ofan image signal, and outputs the modulated lights;
 9. The projectoraccording to claim 1, wherein the control section is further configuredto control gain values, corresponding to the plurality of colors. 10.The projector according to claim 1, wherein the control section isfurther configured to control the plurality of light source sections toemit the lights of the plurality of colors with different light emissiontime periods.
 11. The projector according to claim 1, wherein the atleast one light source section of the plurality of light source sectionsincludes a third light source that is configured to emit lights of thesame color, and the control section is further configured to calculate,based on a difference between a second detection result of the lightquantity detector upon light emission of all of the plurality of lightsource sections and a third detection result of the light quantitydetector upon extinguishment of the one of the first light source, thesecond light source, or the third light source, a light quantity of acorresponding ray emitted by the one of the first light source, thesecond light source, or the third light source.
 12. The projectoraccording to claim 11, wherein in each of a plurality of light emissionperiods of the lights of the same color, the control section is furtherconfigured to: extinguish at least one of the first light source, thesecond light source, or the third light source for a second time period;and measure, at second different timings over the plurality of lightemission periods, the light quantity of the lights emitted by each ofthe first light source, the second light source and the third lightsource, and the light quantity is measured for a plurality of times. 13.The projector according to claim 12, wherein the control section isfurther configured to control the extinguishment of the at least one ofthe first light source, the second light source, or the third lightsource at third different timings that is within a corresponding lightemission period of the plurality of light emission periods.
 14. Theprojector according to claim 5, wherein the first time period is one ofequal to 1000 μs or less than 1000 μs.
 15. The projector according toclaim 1, wherein the control section is further configured to: controlthe plurality of light source sections to concurrently emit the lights,in a second time period except for a third time period in which a lightquantity of each of the lights of the plurality of colors is measured,and extinguish the at least one light source section of the plurality oflight source sections in the third time period, and the at least onelight source section of the plurality of light source sections isconfigured to emit the lights of the same color for a fourth timeperiod.
 16. The projector according to claim 15, wherein the controlsection is further configured to calculate, based on a differencebetween a second detection result of the light quantity detector uponlight emission of all of the plurality of light source sections and athird detection result of the light quantity detector uponextinguishment of the at least one light source section of the pluralityof light source sections, the light quantity of a corresponding rayemitted by the at least one light source section of the plurality oflight source sections.
 17. The projector according to claim 15, whereinthe third time period is one of equal to 1000 μs or less than 1000 μs.18. The projector according to claim 1, wherein the control section isconfigured to: control the plurality of light source sections toconcurrently emit the lights, in the first time period except for asecond time period in which a light quantity of each of the lights ofthe plurality of colors is measured; and extinguish one of the pluralityof light source sections in the second time period, wherein the one ofthe plurality of light source sections emits the lights of the pluralityof colors for a third time period.
 19. The projector according to claim18, wherein the control section is further configured to calculate,based on a difference between a second detection result of the lightquantity detector upon light emission of all of the plurality of lightsource sections and a third detection result of the light quantitydetector upon extinguishment of the one of the plurality of light sourcesections, the light quantity of a corresponding ray emitted by the oneof the plurality of light source sections.
 20. The projector accordingto claim 18, wherein the second time period is one of equal to 1000 μsor less than 1000 μs.